DE1521509A1 - Process for the production of metal structures on semiconductor surfaces - Google Patents

Description

a & Halske Munich 2, 1 ^ .SER 196

Aktiengesellschaft V / ittelcsbacherplata

ΡΛ

66/2859

Ancestors for the production of metal structures Semiconductor surfaces

Addition to: patent. ... ... (patent application S 101 956 VIl) AQtJ PA 66/2123).

Dan Ila main patent. (Patent application

S 101 956 VIb / 401>; ΡΛ 66/2123) aich looks up a method of sun herotolling of very fine structures consisting of a metal layer, inc-

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especially of those for the production of contact surfaces on semiconductor single crystals through full-surface motall separation on the surface to be treated, subsequent covering with an appropriate photoresist and mapping of the desired structures Exposure and development of the photoresist and removal of the areas not covered with an etching mask ft metal layer, with the full-surface Metallaoacheiduijg on the surface to be treated with the addition of at least one further, in particular different from hydrogen Metal having redox potential takes place.

The method on which the invention is based is thereby marked that sun eyrie of the goose tunnels I-metal separation aluminum and as an additional lletall nickel and / or titanium is used.

The method based on the teaching of the invention provides the possibility of reliable etching of the finest Conducting channel geometries from aluminum. Due to the addition of nickel or titanium at the Bodempfui ig achieves that the etching time for the production of the I.Iotall structures about a factor of 2-3 is shortened compared to the etching of pure aluminum layers, which is particularly important favorable to the adhesion of the contact tracks

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covering varnish affects. Eo v / earth without major Effort reproducibly small tasks (smaller 0.5 / u).

Ea iot particular beneficial, weighed the following masked etching, adjust the layer thickness of the full-surface Lletallsehicht to about 1 / u, in particular to 0.5 / u.

Eo is also within the scope of the invention, the ketal separation on the surface to be treated by vacuum evaporation at a pressure of 5-8.10 Torr to undertake.

According to a particularly favorable exemplary embodiment, an alloy of the Mo tal Ic to be evaporated is used.

'■ Λ ·' Λ a concept based on the invention. ^}. ii; n; ^; forri will «or part of the additional motallr: co gew; Ji: lt, fjfjß er i ::. 'iXir: ial 0, ⁽ 3 ^r / o is. Dicrso restriction l :: \ ! iOi-.Ycndi, '- so that the applied Aluiainiumocliiclit j.ioht;: u becomes hard and remains easy to correlate ..

The · Au.l''lanp.i'ungi: bcdingungon be chosen so dai3 the temperature of the vapor-deposition 900-1000 ⁰ G, in particular

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to 90O ⁰ C, is set and the vapor deposition rate is about 30 A / sec. amounts to.

The method according to the invention is particularly suitable advantageous Y / eise for the production of semiconductor components, in particular of silicon planar transistors and diodes and for the production of integrated circuits and field effect transistors.

But it is also advantageous for the production of electrical, multi-pole components such . B. resistors and capacitors applicable.

The following exemplary embodiment and FIGS. And 2 are intended to illustrate the method on which the invention is based are explained in more detail.

In FIG. 1, an approximately 160 / U thick, for example η-doped with antimony, silicon single crystal disk 1 is shown in section, in which a p-doped zone 2 was produced by means of known diffusion and photo techniques. The η-doped zone denoted by 3 in FIG. 1 is produced by diffusion by means of phosphorus through a window (not shown in the figure) etched into the oxide layer on zone 2. At this

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Phosphorus diffusion, becomes the entire silicon crystal wafer provided with a phosphor oxide layer, in which by means of photo technology and buffered hydrofluoric acid solution another window 10 for attaching the metal contact etched according to your method according to the invention is, "so that the parts of the oxide layer on the silicon crystal wafer stop, which are denoted by 4. The region of the semiconductor body marked ir.it 7 represents the metal layer produced according to the invention by a metal deposition over the entire surface, consisting of Aluminum and winding represent. The crystal disc is after the vapor deposition covered with a commercially available photoresist and the desired structures are determined by exposure and development of the photoresist. Afterward the uncovered areas are removed in a conventional etching solution at 60 0 and the crystal disc further processed to produce a silicon planar transistor.

The vapor deposition apparatus used for the process according to the invention is shown schematically in FIG. Before the!, Lethal vapor deposition, the with the different doped zones provided, a plurality of components containing silicon single crystal wafer of the for the Window protection (window 10 in Figure 1) applied

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Photoresist in the usual way "freed. Pure; each evaporation process several crystal disks 12 are clamped in a holder 14 made of tantalum sheet, placed in a vapor deposition apparatus consisting of the resipients 11, as shown in FIG Arrow an 01 diffusion pump is connected to evacuate the resipient 11. A Yfolfram coil 16 is used as the evaporator for the metals to be deposited, into which an alloy 17 consisting of aluminum with a content of 0.5 ^c f> nickel has been introduced However, an aluminum run pill (approx. 270 mg) can also be used, which is melted with a small piece of nickel sheet (0.1-0.5 mg) of appropriate purity in a vacuum 100 mm. The V / olfactory helix 16 with the alloy 17 is now brought to a temperature with the shutter 10 closed by means of the power supply lines 19 r brought in which the alloy evaporates continuously, e.g. B. to about 900 G. If the pressure in the recipient is 5-8.10 "Torr, the metal alloy 17 located in the V / olframondel 16 is evaporated at a speed of 30 Λ / sec. And up to to the desired

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Layer thickness of f, for example, 0.5 / U on the in the Craper 14 clamped crystal disks 12 deposited.

After the removal from the recipient, the Immediately coat the crystal disks with a commercially available photoresist in a layer thickness of approximately 0.5 / U provided and dried at 90 ° C for 15 minutes. Then the photovoltaic layer is made according to the desired structure exposed by means of a 2u adjusting mask and subsequently developed. The desired geometry is retained as a varnish structure and is used during the Etched shoots as a protective coating or etch mask. The Xxistall disks are in an alkaline solution, see B. in Above potassium carbonate solution at 60 C, approx. 10 minutes etched, the for the production of contact surfaces The finest interconnecting elements necessary on Plar are preserved under the? otolackcchicht with excellent KoiiVurc-nschtirfc and evenness.

3 Fritei'itanspriiohc

2 figures

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Claims (9)

Claim ο 1. Ancestors of manufacturing from a metal layer existing, very fine structures, especially those used to create contact surfaces on semiconductor crystals through volatile Lethal separation on the surface to be treated, subsequent covering with a corresponding one Photoresist and imaging of the desired structures through exposure and development of the Photoresist and detachment of the areas of the metal layer not covered with an etching mask, the full-area metal deposition on the surface to be treated with the addition of at least one additional, in particular compared to hydrogen having a different redox potential of metal takes place according to Patent. (Patent application S 101 956 VIb / 48b; PA 66/2123), characterized in that for manufacturing the entire metal deposition is aluminum and, as an additional metal, nickel and / or titanium be used. BATH ORIGINAL 909838/051 3 ΡΛ 9/493 / 818a - 9 - 2. Tc rf ear on according to claim. 1, characterized in that the layer thickness of the applied metal layer is approx. 1 / Xi, in particular 0.5 / U. 3. The method according to claim 1 and / or 2, characterized in that the JJctallabschcnahm on the to be treated Surface by evaporation in a vacuum 5 - 8.10 Torr. 4. The method according to at least one of claims 1 bin 3, characterized in that a vapor deposition source Alloy of eu evaporating metals is used. 5. The method according to at least one of claims 1 to 4, characterized in that the proportion of the additional metal in the source is a maximum of 0.5 ü '. 6. The method according to at least one of claims 1 to 5, characterized in that the temperature of the vapor deposition source is set to 900 ~ 1000 ° C, particularly 900 ° C. 7. The method according to at least one of claims 1 to # s6, characterized in that the vapor deposition rate is reduced to approximately 30 Å / Sok. is set. - 10 - 909838/0513 ΡΛ 9/493 / 81Ba - 10 - 8. Use doc procedures after at least one of claims 1 to 7 »for the production of semiconductor components, in particular from silicon planar transistoreiT. and diodes Gov / ie for the production of integrated circuits and field effect transistors. 9. Use of the method according to at least one of claims 1 to 7 for the production of electrical, multi-pole components v / i ο ζ. Β. Resistors and capacitors. BATH ORIGINAL 909838/0513